1. Technical Field
The invention relates to an image display apparatus and a method of manufacturing the image display apparatus.
2. Related Art
The image display apparatus described above is used in a head mounted display (HMD), for example, as described in International Publication No. 09/041055. Specifically, as illustrated in FIGS. 14A and 14B, the image display apparatus includes a light source 102 of a semiconductor laser beam or the like configured to emit light, a scanning mirror 103 configured to reflect light from the light source 102 onto a reflective diffraction optical element 104 composed of a MEMS device or the like and onto the reflective diffraction optical element 104 configured to deflect light from the scanning mirror 103 by diffraction and enables observation of the deflected light as a 1st order diffraction ray.
FIG. 14A is a schematic plan view of an image display apparatus which constitutes part of the head mounted display viewed from above. FIG. 14B is a schematic side view of the image display apparatus illustrated in FIG. 14A viewed from the side. Only an optical system for a right eye is illustrated as an example. In this configuration, a video image can be observed simultaneously while viewing the background by applying a transparent property.
However, as illustrated in FIGS. 14A and 14B, there is a case where a 0 order diffraction ray (image light) which is regularly reflected by the reflective diffraction optical element 104 enters an opposite eye (left eye) to the eye on the optical system side (right eye), for example. Accordingly, unintended and unnecessary light enters the left eye, and hence there arises a case where the quality of a displayed image is lowered such that a bright point (ghost image, for example) is seen.